The present invention relates to a wrench with a hollow handle. More particularly, the present invention relates to a wrench with a reinforced hollow handle.
Wrenches are widely used in daily life. FIG. 14 illustrates a conventional wrench including a head 1, a neck 2, and a handle 3. The head 1, the neck 2, and the handle 3 are integrally formed by forging and have a solid structure, which results in high manufacturing cost and a heavy wrench. The solid handle 3 is the largest element of the wrench and, thus, a burden to the user, which may lead to low working efficiency.
FIG. 15 illustrates another conventional wrench of the type having a head 5, a neck 9, and a hollow handle 4 to reduce the overall weight of the wrench and to cut the manufacturing cost. However, the wrench cannot withstand large torque. Specifically, the hollow handle 4 includes a joint portion 6 having a smaller outer diameter and connected with the neck 9, a gripping portion 7 having a larger outer diameter, and a necking portion 8 between the joint portion 6 and the gripping portion 7. The gripping portion 7, the necking portion 8, and the joint portion 6 have identical wall thicknesses. However, the joint area between the joint portion 6 and the necking portion 8 are liable to break due to torque and shear force generated during driving a fastener.
The present invention is intended to provide a wrench with a reinforced hollow handle portion to withstand larger torque during operation while having a reduced overall weight without significantly increasing the manufacturing cost.